There is a large body of research on cognitive interventions for older adults the review which suggests the following: (1) Cognition remediation therapy is indicated for healthy elderly, and in mild cognitive impairment (MCI), early dementia, brain disease and injury, and severe mental illness (SMI). (2) Studies on healthy elderly demonstrate that with cognitive training (CT), cognitive stimulation (CS), and/or cognitive rehabilitation (CR) age-related cognitive decline can be reversed, at least partially if not fully, even in advanced age, with improved social functioning and quality of life. Better results are obtained if cognitive remediation therapy (CRT) is combined with vocational/psychosocial rehabilitation. Generalization of training to activities of daily living (ADL) and to secondary outcome measures such as quality of life and self-esteem are issues that need to be addressed in older adults. (3) Research in MCI has indicated that CRT, especially memory training, has some role. Future studies should place focus on the assessment of dose-response relationship, training generalization, and ecologically relevant approaches. (4) Findings of earlier work in early-stage dementia were frustrating, more recent work, especially randomized controlled trials of high quality, has provided a ray of rope with respect to effectiveness of CT and CR. Further well-designed studies are required to provide more definitive evidence. (5) Significant therapeutic effects of CR have been observed on cognitive function and ADL in the elderly patients with stroke. Routine screening for stroke patients and those with brain injury for cognitive impairment is recommended. (6) Available research provides evidence that cognitive remediation benefits people with SMI, and when combined with psychiatric rehabilitation this benefit generalizes to functioning. Elderly with SMI need special focus. Further needs to be carried out on older people with SMI.

As the population ages, risk for cognitive decline threatens independence and quality of life for older adults and presents challenges to the health care system. Research on determinants and covariates of cognitive status in older people suggest that cognitive decline, to some extent may be reversible. [1] Sustained engagement in cognitively stimulating activities has been found to impact neural structure in both older humans and rodents. [2],[3] Both human and animal studies indicate that neural plasticity endures across the life span and that cognitive stimulation (CS) in the environment is an important predictor of enhancement and maintenance of cognitive functioning even in old age. [4] The available agents for Alzheimer's disease (AD) are only symptomatic treatments for AD; there is no cure for AD. Besides, compliance to such treatments is limited by possible adverse effects. Thus, the most promising avenues of intervention now lie in prevention.

Furthermore, a growing body of research supports the protective effects of late-life intellectual stimulation on incident dementia. [5],[6] Cognitive reserve is generally known to delay the cognitive and functional expression of neurodegenerative diseases. In this sense, CS/training programs might have an impact on cognitive reserve, by optimizing normal performances, in agreement with the already known effect of education level. [7],[8]

It is evident that maintenance of cognitive functions in old age has become increasing important to human society with an aging population. "Brain health" programs developed by aging interest groups such as the American Association of Retired Persons and the Alzheimer's Association provide directives on cognitive activities, in addition to other advice. [9] Assuming that "use it or loose it" principle applies to cognitive health, computer training memory tapes, and Nintendo games are marketed to the lay people with claims of enhancing cognition. [10],[11]

Over the past two decades, several studies have documented the beneficial effects of cognition enhancement techniques in different populations of older adults with cognitive impairment. This paper shall examine and present the current status with respect to the same.

Types of cognitive interventions

Cognitive interventions are based on two major approaches. The restorative approach (direct intervention/process specific) is based on the theory that repetitive exercise promotes recovery of damaged processes and restores lost function. The compensatory approach (functional approach) focuses on teaching patients to employ various strategies to cope with underlying cognitive impairments and accompanying social deficits. Among the different types of cognitive interventions, cognitive training (CT), cognitive rehabilitation (CR), and CS are most common. [12] CT typically involves guided practice of standard tasks to increase or maintain particular cognitive functions such as attention or problem solving. [13],[14] Recently, the definition of CT has been broadened to include strategy training, which involves the instruction and practice of strategies to minimize cognitive impairment and enhance performance (for example, method of loci and visual imagery) and cognitive exercise. [15] Tasks may be presented in paper and pencil [16],[17],[18] or computerized [19] form or may involve analogs of activities of daily living (ADL). [20],[21] CT may be offered through individual [17],[21] or group [22],[23] sessions or facilitated by family members [21],[24] or with therapist support. In accordance with the suggestion that CT may enhance the effects of pharmacological therapy, [25] some workers have evaluated the efficacy of CT in combination with acetylcholinesterase-inhibitors [23] or other [26] medications. In addition, CT for persons with dementia has sometimes been included as a component of supportive interventions for caregivers. [27]

CR also involves the practice of some tasks, but generally prioritizes personal goals as targets in order to improve, one at a time, specific impairments in everyday life. [12],[13],[29] CR offers retraining in the ability to think, use judgment, and make decisions [30] and helps brain-injured or otherwise cognitively impaired individuals to restore normal functioning or to compensate for cognitive deficits. CS promotes the involvement in activities that are aimed at general enhancement of cognitive and social functioning, without specific objectives. [12],[13],[29]

Cognitive remediation therapy (CRT), also called cognitive enhancement therapy, is designed to improve neurocognitive abilities such as attention, working memory, and executive functions, including cognitive flexibility and planning, which leads to improved social functioning. [31] Metacognitive training provides awareness and knowledge and focuses on strategies for problem solving. [32]

Other types of cognitive interventions include: "Training in specific tasks" such as systematic training of routines, [31] interventions with help of "virtual reality" - for training specific abilities such as memory, attention or of functional tasks (such as crossing the street, [33] and "Training in social abilities" such as parent-child relationships or relations with peers. [9]

Tailoring of task difficulty on the basis of the individual performance level is becoming increasingly available through computerized packages. Brain Function therapy for cognitive remediation has been developed at the National Institute of Mental Health and Neurosciences, Bengaluru, India, by Mukundan. [34] It may be noted that these approaches are complementary, and the choice of a particular approach depends on the objectives of cognitive enhancement or maintenance and on the cognitive profile of the population targeted. [29]

Interest in cognitive remediation techniques in elderly have increased with a growing understanding of the impact of cognitive impairment on loss of independence in day to day function. In recent years, several studies have assessed the efficacy of different cognitive interventions in the elderly and reported beneficial effects, [35],[36],[37],[38],[39],[40],[41],[42],[43] even in advanced age, [41],[44] which could be maintained for a considerable period of time beyond training. [4],[39],[40] The focus of interventions in these studies was memory and related functions.

The effect of mnemonic (organizational strategies) training on recall has been explored extensively. About 3 mnemonic strategies the method of loci, the use of imagery and techniques for processing new information more accurately, have been especially influential. [1] However, the effects of teaching mnemonics are task specific and limited to the immediate posttraining period. [1]

Multifaceted training that combines three relatively diverse strands of therapy: A form of counseling/behavior therapy to target psychosocial variables (self-efficacy beliefs, feelings of control, and optimism), CT to target cognitive functions and complimentary physical activity, appears to have some benefit in maintaining a higher level of cognitive function over time. [1]

The value of CT for specific cognitive abilities that normally decline in aging is provided by the Seattle Longitudinal Study. [45] Older adults with existing declines in either inductive reasoning or spatial orientation performance were provided with a brief (5 h) training program. Two-third of the participants demonstrated improvement with 40% returning to a baseline level obtained 14 years earlier. Ongoing effects continued up to 7 years after training.

The Advanced CT for Independent and Vital Elderly (ACTIVE) randomized controlled clinical trial provided strong evidence of effectiveness CT. The participants of the trial were 2000 healthy, community-dwelling older adults. Ten training sessions were provided for verbal episodic memory, inductive reasoning, or processing speed. Immediate post-training improvements occurred in the specifically targeted skills, and with booster sessions 11 months after initial training, improvement continued for 2 years. [4] The 5-year follow-up for the ACTIVE study found that four booster treatments resulted in both better performance on the specific domains and in less functional decline in instrumental ADLs (IADLs) for the inductive reasoning group. [46] Besides, experimental (versus control) group participants were less likely to suffer significant declines in health-related quality of life. [47] These findings are intriguing provide a lead for ongoing research to test the impact of cognitive interventions on daily lives of older adults.

The review of research evaluating the effect of cognitively stimulating lifestyles on cognitive function of older adults suggests that overall research findings support positive effects of cognitive and physical activity, social engagement, and therapeutic nutrition in optimizing cognitive aging. However, the strength of the research evidence is limited by research designs.

Stuss et al. [48] adopted scientifically based principles of strategic processing for developing a program to improve general strategic abilities in older adults who had experienced normal ARCD. It focused on the development of basic and practically oriented strategies for learning, remembering, and problem-solving, combined with an explicit emphasis on enhancing psychosocial well-being. It consisted of three distinct 4-week modules, administered over 12 weeks; a group format was adopted in which individuals as a group met weekly in relatively short (3 h), highly interactive sessions and assessed performance in the domains of memory, goal management, and psychosocial stress. The authors concluded that changes in strategic processing can be trained in the elderly and that any changes observed were the direct result of rehabilitation.

The results of the cognitive intervention programs administered to healthy elderly in the past 10 years, until March 2011, were reviewed. [49] The efficacy of 14 cognitive intervention programs administered to healthy elderly participants was examined. Nine out of 14 studies targeted memory as the principal cognitive function to train or stimulate. Face-name associations, mental imagery, paired associations, and the method of loci were the main techniques taught to participants. Improvements were observed on at least one outcome measure in each study included in this paper. Important suggestions for future work were the utilization of more robust experimental designs, the inclusion of measures of generalization of training in daily life, and the assessment of IADL, quality of life, and self-esteem.

CR in elderly has been studies in relation static balance. During balancing, there is interaction of sensory processes among the somatic senses, including proprioception, visual sense, and stereotactic input from the vestibular system. [50] Reduction of balance ability due to aging has been reported to be associated with cognitive function [51] and slowing of central information processing speed. [52] Lee et al. [53] in a randomized controlled study investigated the effects of a 6-week-long computer-assisted CR training program on the improvement of cognition and balance abilities of the elderly. Computer-assisted CR training was found to an effective intervention method for the improvement of the cognition and balance abilities of the elderly.

In summary, the available data suggest that cognitive remediation therapies have great promise for improving cognition and quality of life of elderly.

Mild cognitive impairment

The rate of AD is expected to increase 2-3-fold in the coming decades. [54] In response to this challenge, two important developments have taken place. First, attempts to identify at-risk patients before the onset of AD. Thus, MCI that captures cognitively symptomatic individuals who are likely to convert to AD was accepted as a diagnosis by the National Institute on Aging's and the Alzheimer's Association's [55] and the American Psychiatric Association's. [56] Second, attempts are being made to identify pharmacologic and nonpharmacologic interventions that can enhance, maximize, or otherwise prolong functioning in at-risk patients. This is especially important since there is often a multi-year period of cognitive stability between conversion from "healthy" to MCI and subsequent progression to AD. [57],[58],[59]

Debate continues on the extent to which pharmacological agents impact cognition and conversion rates. Explicit learning and memory represent the characteristic areas of impairment in MCI and also the focus of techniques of CR. This paper will focus on nonpharmacologic approaches to MCI.

A Cochrane Review of randomized controlled trials (RCTs) in those with MCI found no benefit of cognitively based interventions relative to control conditions. [60] However, this conclusion was based on only three studies that used a wide variety of techniques. Subsequently, at least seven reviews [61],[62],[63],[64],[65],[66],[67] and one meta-analysis [68] over a period of 3 years studies have indicated that patients could benefit from CR of memory. Thereafter, a quasi-experimental randomized controlled study [69] with test-retest design from Iran evaluated the effectiveness of CR on selective attention in patients with MCI in older adults. CR comprised 12 sessions (2 h each section) of CR with the Neurocognitive Joyful Attentive Training Intervention. The results indicated that CR can impact on improving selective focus in people with MCI.

Hampstead et al. 2014 [70] carried out a methodological review of 36 studies of CR of memory for MCI and outlined the methodological pitfalls of the studies such as diagnostic variability, use of multitechnique approach, variability of outcome measures, and need for assessment of dose-response relationship and training generalization. They suggested that future studies should place greater emphasis on ecologically relevant approaches and suggested a hierarchical model that may aid in this pursuit.

In conclusion, although earlier studies were not encouraging, several later studies do indicate that many patients may benefit from CRT.

Alzheimer's disease and vascular dementia

Interventions to assist with aspects of cognitive functioning and associated functional limitations are important in the milder stages of AD or VaD as they may allow the person greater independence and can possibly minimize the risk of "excess disability." Interventions for people with mild dementia can be pharmacological, nonpharmacological, or both. There is considerable doubt that disease-modifying drugs can show a positive effect by the time dementia is fully developed. [71] On the other hand, nonpharmacological interventions and particularly cognition-based interventions are increasingly being recognized as an important adjunct (and, in some cases, alternative) to pharmacological treatments for individuals with dementia and those at risk of dementia.

Earlier studies suggested that cognition-based interventions are not appropriate as they are ineffective and result in frustration and depression for participants and caregivers. [72] However, with a growing emphasis on early detection and intervention in dementia care, there is a need for a clear evidence base for cognition-focused interventions.

CT and CR are specific forms of nonpharmacological intervention to address cognitive and noncognitive outcomes in persons with mild to moderate AD or VaD.

Some recent studies have reported positive results, for example, CR may help people with dementia to maintain residual memory ability by identifying the best way to obtain important information. [73],[74],[75] Besides, in patients with mild AD, several learning techniques and strategies such as spaced retrieval, dual cognitive support, and procedural memory training have been demonstrated as methods to enhance learning ability [76],[77],[78] and CT was demonstrated in people with early stage dementia to have an effect on memory, mood, and analogs of ADL. [17],[18],[22]

A recent Cochrane review that focused on interventions concluded that general CS and reality orientation approaches consistently produce improvements in general cognition and in some cases, in self-reported quality of life and well-being, primarily in people with mild to moderate dementia. [79]

Bahar-Fuchs etal. 2013 [28] systematically reviewed the evidence for interventions in people with mild AD or VaD. RCTs, comparing CR or CT interventions with control conditions and reporting relevant outcomes for the person with dementia or the family caregiver (or both), were considered for inclusion. Eleven RCTs were included in the review. CT was not associated with positive or negative effects in relation to any of the reported outcomes. The overall quality of the trials was low to moderate. The single RCT of CR found promising results in relation to some patient and caregiver outcomes and was generally of high quality. Further well-designed studies of CT and CR are required to provide more definitive evidence.

In a recent randomized controlled study, [31] it was found that CR rehabilitation including tasks of CT is an effective intervention for improving occupation performance and satisfaction with respect to ADL and specific cognitive functions (orientation subscale of Mini-Mental State Exam).

In conclusion, the findings of earlier work in early dementia (AD and VaD) were frustrating. However, recent data, especially from a high-quality RCT, has provided a ray of hope.

Traumatic brain injury or brain disease

According to the World Health Organization, about 15 million people have a stroke worldwide annually. Five million of survivors are left permanently disabled, [80] with complications including motor (50-83%), cognitive (50%), language impairments (23-36%), and psychological disturbances (20%). [81]

Cognitive impairment is a frequent consequence of stroke. CR following a stroke can make the difference in a full or partial recovery. Recent studies show that rehabilitation is responsible for more than 70% of the recovery process. [82] CR offers retraining in the ability to think, use judgment, and make decisions. The focus is on correcting deficits in memory, concentration and attention, perception, learning, planning, sequencing, and judgment. [83] Stroke survivors may greatly benefit from CR treatment to decrease their cognitive deficits. [84]

A quasi-experimental controlled study [82] at Assiut University Hospital Egypt evaluated the effect of CR of elderly patients with stroke on their cognitive function and ADL. Significant therapeutic effects of CR were observed on cognitive function and ADL in the elderly patients. Routine screening of stroke patients for cognitive impairment was recommended.

Severe mental illness

Elderly persons may develop SMI in old age or the same may be carried into senescence. Recognition that cognitive deficit is a major determinant of outcome in people with severe, chronic mental illnesses has generated considerable interest in cognitive remediation. [85] Most of the research work on SMI has been done in young people and adults. People with severe SMI are disadvantaged in many ways; by old age, SMI, delirious effects of psychotropic medication, and by the negative attitude of the society. This group needs special attention. Thus, the research work CR in SMI is presented as the same can be applied as such in older adults or with suitable modifications. It may be noted that efforts to improve cognitive functions in SMI devolved from applications in the rehabilitation of people with brain injury.

Most people with SMI have cognitive impairments which tend to be stable over time and do not respond to currently available pharmacotherapy. Cognitive impairment has been reported in many areas including attention, psychomotor speed, working memory, verbal learning and memory, and executive function [86],[87],[88] and has been reported to be related to several parameters of poor outcome. [89],[90] Alternatively, better cognitive functioning predicts better work outcomes. [91]

Metacognitive training, which focuses on building knowledge and ability to use problem-solving strategies, is a useful approach for persons with SMI. [32] Some programs supplemented individualized cognitive exercises with group practice activities. [92],[93],[94],[95] Most cognitive remediation programs provide a minimum of 2 h per week of practice and require 3-6 months to complete. [96]

In current approaches to cognitive remediation, multiple domains are generally targeted by computerized tasks or paper and pencil exercises, designed to provide practice of cognitive skills in order to restore or improve them. [97] A laboratory facilitator, or cognitive specialist, generally monitors task performance, provides encouragement for effort, help with problem-solving tasks that are challenging or frustrating, and positive reinforcement by pointing out progress. The cognitive specialists may also provide instruction, or strategy coaching, for example, on methods for improving attention (e.g., talking out loud through a task) or learning (e.g., breaking up material into manageable chunks). [97] Recently, meta-analysis of work done in this area concluded that cognitive remediation was related to improved community functioning. [98]

More recent efforts have focused on combining cognitive remediation with vocational rehabilitation. [92],[99],[100] Researchers evaluated the effects of combining neurocognitive enhancement therapy, [92] Computer-Assisted Cognitive Strategy Training, [99] and the Thinking Skills for Work Program (CR program with supported employment) [91] with community-based vocational rehabilitation. [100] The results from these studies indicate improvements in both cognitive and work functioning. However, in these studies, characteristics of participants, the vocational rehabilitation models, and the methods of combining cognitive and vocational therapies varied considerably. There are other approaches to cognitive and vocational rehabilitation such as errorless learning and CT to compensate for cognitive impairment, etc. [98] A meta-analysis [101] including 2104 participants concluded that cognitive remediation benefits people with schizophrenia, and when combined with psychiatric rehabilitation, this benefit generalizes to functioning. A recent overview of CRT for people with SMI has found it be effective, especially if combined with vocational rehabilitation. [85]

Conclusion

There is a large body of research on cognitive interventions for older adults.

Studies on healthy elderly demonstrate that with CT, CS, and/or CR ARCD can be reversed, at least partially if not fully, even in advanced age, with improved social functioning and quality of life. Better results are obtained if CRT is combined with vocational/psychosocial rehabilitation. Generalization of training to ADL and to secondary outcome measures such as quality of life and self-esteem are issues that need to be addressed in older adults

Research in MCI has indicated that CRT, especially memory training, has some role. Future studies should place focus on the assessment of dose-response relationship, training generalization, and ecologically relevant approaches

Findings of earlier work in early-stage dementia were frustrating, but more recent work, especially an RCT of high quality, has provided a ray of rope with respect to effectiveness of CT and CR. Further well-designed studies are required to provide more definitive evidence

Significant therapeutic effects of CR have been observed on cognitive function and ADL in the elderly patients with stroke. Routine screening for stroke patients and those with brain injury for cognitive impairment is recommended

Available research provides evidence that cognitive remediation benefits people with SMI, and when combined with psychiatric rehabilitation this benefit generalizes to functioning. Elderly with SMI need special focus. Further needs to be carried out on older people with SMI.